When teaching a skill like adding money amounts to create a total it is tempting to tell students the way that they "should" do this problem or the way that is easiest (for you) to do this kind of problem. For me, it makes the most sense to add up money amounts using column addition--this strategy seems efficient and builds on my students' previous knowledge of adding two digit numbers together using regrouping. However, I challenged myself to have my students develop their own ideas and strategies for this kind of problem and I was amazed by what kind of strategies my students were drawn to and how these strategies worked for them!

Since we had spent the previous class periods focused on adding coin amounts several of my students simply broke the money amounts down into coins and then skip counted to find the answers. Others broke the money amounts into tens and ones (dimes and pennies) and added that way. A large group of students added using column addition, but some added all three amounts while others simply added two numbers together and then added the third addend to the sum of the first two.

By giving my students the freedom to determine their strategy and not forcing "my strategy" on them, my students were able to develop a strong conceptual understanding and further, were able to enter into this problem at a level that was appropriate for them (i.e: my highest achieving students conceptually understood why they should add up the three addends using column addition while other students needed to break the amounts down into coins to visualize the problem).

This lesson was the first in a two day sequence on adding money amounts and by the end of the sequence, many students were using "my strategy", however, they took their own road to realize that adding the money amounts using column addition was an efficient way to get an accurate answer.

I start class by displaying a poster entitled "School Store". This poster has pictures of items with their prices.

I have some items for sale at my school store. Who can tell me what three items they would like to buy from the school store.

I have a student pick three items.

I saw some ice cream for $.17. I saw an eraser for $.40. I saw a bouncy ball for $.30. If I want to buy all three items, how much money do I need?

I hand out white boards to students and allow them to work individually or in partners to solve this problem to the best of their abilities. Coin manipulatives and cubes are also available to students.

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After students have had 3-5 minutes to work on the problem, I ask them to turn to their partners and share how they solved the problem.

Turn and Talk: How did you solve this problem? What strategies did you use?

As students discuss, I circulate to listen for students' strategies and any common misconceptions. Some students might add using column addition, others might add two of the addends and then added the third to the sum. Others might visualize the addends using coins and skip count.

When finished, I ask two or three students to share their strategies.

As students share, I make sure that they are modeling how to solve this kind of problem and WHY they chose their specific strategy. I make an anchor chart of students strategies for future use.

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Independent practice is tiered based on facility with money. As students work make sure that they are attending to precision and being accurate in their work. (MP6)

Group A (In need of intervention)

Students in group A will work with teacher support to add money amounts that require little to no regrouping. If adding using column addition, this group will be encouraged to add only two items at once and then add the sums together in order to improve accuracy.

Group B (Right on track!)

Students in group B will work independently or in partners to add money amounts using regrouping. Remind students in this group to pay attention to their decimal point and line the numbers up correctly.

Group C (Extension)

Students in group C will work independently or in partners to add money amounts using regrouping. This group will be challenged to add money amounts where the total is greater than $1.00.

See: Student strategies In this video, two students add the coins using column addition, two others draw and group the coins.

Big Idea:
Most students think of money when they’re asked where they see math in their world. While money is all around them, they rarely get to use it themselves. This lesson reviews coin identification